Valve-silencing mechanism



G. A. SUFFA.

VALVE SIL'ENCING MECHANISM.

APPLICATION FILED JULY 14,1921.v

1,411,387. Patented Apr. 4, 1922.

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-. GEURGE A. SUEFA, OF BOSTON, MASSACEU$ETT$.

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Mechanisms, of which the following is a specification.

My invention relates to the means for actuating the valve mechanisms ofmotors, more especially those of the internal combustion types, and hasas its particular object to provide a construction which w1ll serve totake up the lost motion. in the said mechanism,and in that manner toeliminate theclicks and similar noises commonly noticed in valvemechanisms of'the prior types.

My invention is described in the specification, having reference thereinto the accompanying drawings, forming a part of this application.

In the said drawings, wherein 1 have shown my invention in several ofits preferred forms; 4

Figure 1 is an elevation, partly in longitudinal section, showing myinvention as the same is applied. to a motor having the socalledoverhead type of valve, which is operated through a rocker'arm.

Figure 2 is a plan view of the underside of the rocker arm which forms apart of the valve mechanism shown in Fig. 1, with the shoe supportattached thereto.

7 Figure 3 is a view of the hinge side of the shoe forming a part of myinvention.

Figure 4: is an elevation, partly insection, showing my invention a thesame is applied to the valve mechanism of a motor having cylinders ofthe so-called L- or T-head type.

Referring to the drawings; the valve 1 is arranged to lift with respectto its valve seat 2 formed in the valve chamber wall 3; the said valvebeing guided and. centered by its stem 4: which is arranged to slidelongitudinally within the guide-bushing 5 mounted upon said wall castin3'. A. valve sprlng 6, maintained in a state 0 compressmn, hold saidvalve 1 closed upon its seat 2, except as the same is raised againstsaid spring 6 by the action of the valve mechanism Said valve spring 6,in its usual embodiment encircles the valve stem 4:, and is confinedbetween an inner plate or washer 7, lying ad jacent the inner end of theguide bushing 5, and a plate 8 fixed longitudinally with re-Specification of Letters Patent. Patented Apr. it, 1922,

Application filed. July it,

met. Serial No. eaters.

spect to the valve stem 1; as by a pin 9., or other approved means ofattachment.

The valve actuating mechanism may be of any approved type. As shown in Figures 1 and a it includes a cam 10 rotating with the cam shaft 11, andengaging a roller 12 carried in the forked'end 13 of a valve tappet 13which is longitudinally slidable in a guide 14 mounted in the motorframe 15.

The foregoing descriptive matter, although more especially directed tothe construction shown in Figure 1, will apply with equal pertinence anddescriptive effect to the construction which is shown in Figure 4. Inboth said Figures 1 and a similar parts are identified by similarnumerals; it being noted, however, that in Figure l the valve is shownin a closed position, whereas in Figure ithe valve i shown. raised orunseated.

The chain of connections by which the valve actuating means transmitsits valve unseating movements to the valve, includes a rod 16 whichengages at its lower, (as viewed in Figure 1) end, the tappet 13, and atits upper end carries the ball or spherical knob 16*. Said knob 16 isadapted to engage within a recess 17 provided in the lower end of anadjustable set screw 17 carrying the check-nut 18, which is mounted by athreaded engagement in one end of the rocker arm 19. Said recess isformed with a contour which substantially conforms with that of the knob16 so that the engagement between the rod 16 and said rocker arm endthrough the said screw 17 is essentially of the ball and socket type.

The said rocker 19, which is mounted upon the journal or pivot 20carries in its other arm the shoe support 21 and the shoe 22, in theform and cooperative functioning of which reside the more essentialfeatures of my invention. Said shoe support 21 comprises a, stud portion21 (which engages within a hole formed in said rocker arm end, and issecured therein as by the nut 23) and a lower portion formed with aconvexly curved face 21' which is preferably substantially of the formof a portion of a cylinder extending along the width of said lowerportion; the axis of said cylinder being in the line of vision of theobserver looking at said Fi ure 1.

aid lower portion carries,'attached thereto, by a hinge connection lyingsubstantially parallel with the axis of said cylindrical face 21", theshoe 22 having the characteristics hereinafter described. Said shoe 22is attached to said shoe support by means of the resilient arm or spring22, which is preferably formed separately of the shoe and is attached atone end to the upper portion of the shoe by any approved means ofattachment, as by the screw 24. If desired, however, said spring arm 22may be formed as an integral part of said shoe, as it is shown in Figure4.

The other end of said spring arm 22 is attached to said shoe support yan easily engaged but secure connection, preferably" one in the natureofa hinge. To that end the free end of said arm is fashioned so as tocombine with a suitable projecting portion of the shoe support informing a hinge ofwhich the hinge members are held together by the hingepin 25. Such connection of the hinge type is not, however, essential andsaid arm 22* may be fixedly at tached at its end to the shoe support inany other approved manner.

The said spring arm 22 is of curved form, as shown in the figures, withits upper surface closely approximating the curvature of the face of thecylindrical portion of the shoe support, to which it is arranged to lieclosely adjacent. Further the hinge pin 25 is so located that theadjacent surfaces of said spring arm 22' and of the said cylindricalportion 21 come into contact with one another at a point adjacent saidhinge pin, but with a gradual separation of the same as the distancefrom said pin increases. In the drawings such separation is shown inexaggerated degree in the interest of clarity of the drawings, but inpractice the separation is very slight and the said surfaces lie I veryclosely to each other.

The lower face 22 of said shoe is preferably in the form of acylindrically convexed surface which is arranged to make contact, in theassembled valve mechanism, with the plate 26 carried upon the end of thevalve-stem, in the construction shown in Fig. 1, or withthe upper faceof an adjustable cap-screw head 27 carried upon the valve tappet in theconstruction shown in Figure 4; the point or line of such contact lyingto the left of the axis of the valve stem as shown in the figures. Bturning respectively the set-screw 17 (of igure 1) or the cap-screw 27(of Figure 4) the said shoe is caused to bear correspondingly againstthe said plate 26 or said cap-screw 27 with a force calculated to flexsaid arm 22" insufficient degree to produce a pressure, resilientlyexerted through said shoe 22 upon said plate or cap-screw head, by whichall lost motion in the valve mechanism is taken up.

While the spring arm 22 should possess makes contact.

of said shoe are so coordinated that when that degree of stiffness whichis requisite to producing the pressure necessary to the taking up of thelost motion, at the same time it must be of a weakness calculated to bedominated by the valve spring; that is, said spring arm must bend, asthe valve mechanism actuates to raise the valve, prior to the yieldingof the valve spring 6. Owing to the close correspondence of thecurvature of the upper surface of the spring arm and of the adjacentface of the cylindri-. cal portion 'of the shoe support, the bending ofthe spring arm will cause the closing together of the same, at first'inthe vicinity of the hinged'end of the said arm and then at points orlines which gradually increase in distance from the hinged end of thearm 22; and such bending of said arm and'the closing of the sametogether and into contact with said shoe support is arranged to continueuntil the point or line of contact between the same comes into the planewhich substantially lies coincident with the axis of the valve stem.

During the bending of said spring arm 22 such change in the inclinationand posi-- tion of the said shoe carried thereon as may result iscaredfor by a rolling or sliding action between the lower convex surface ofthe shoe and the surface of the plate 26 or the head of the cap-screw 27with which it The conformation of said adjacent surfaces of said arm andsaid cylindrical portion, and of the convex surface the flexing of saidspring arm has proceeded to the stage where the line or point of contactof the same'with the shoe support substantially reaches and coincideswith the plane lying at the axis of the valve stem the change ofposition of said shoe causes its lowersurface to make contact with theadjacent surface of the plate 26 or the capscrew head 27 along a pointor line which lies substantially in the same plane. In con- 1 0 sequencethe motion imparted to the shoe support by the valve actuating mechanismis communicated by a direct thrust through said shoe to the valve.

It will be'noted that in the construction 5 shown in Figure 4 the shoesupport 21 is carried upon the end of the valve stem 4;

' the same being attached thereto-in any apmines? and said arm havingsurfaces arranged, as said arm is initially flexed, to contact for aportion of the length of said arm adjacent the point of its attachmentwith said support, and as a further flexing of said arm occurs arrangedto effect a shifting of said shoe into a position wherein it becomesoperative to transmit the further valve opening movement of theactuating means to the valve.

2. In valve mechanism for motors and the like, a valve, valve operatingmechanism which includes actuating means and a train of connections forcommunicating the valve opening motion of the said actuating means tothe valve, said train of connections including a shoe supportand a shoesupported thereon through a resilient arm, said shoe being normallycarried upon said support with its arm under flexure in a degreesuiiicient to take up the lost motion in the train of connections, saidshoe arm and said support being so conformed and attached to each otherthan an additional flexing of said arm causes said shoe to graduallyshift into a position wherein it comes into rigid contact with saidsupport and thereafter becomes effective to transmit the further motionof the valve actuating means to the valve.

3. In valve mechanism for motors and the like, a valve, valve operatingmechanism which includes actuating means and a train of connections forcommunicating the valve opening motion of the said actuating means tothe valve, said train of connections including a shoe support and a shoesupported thereon through a resilient arm, said arm be ing normallymaintained in a condition of 'flexure adapted to cause said shoe to bearagainst the connections contiguous therewith with a pressure sufficientto take up the lost motion in said train of connections, and meanswhereby the valve opening motion of said valve actuating means producesan additional flexing of said arm whereby said shoe is shifted into aposition in contact with said shoe support wherein it becomes effectiveto transmit the further motion of the valve actuating means to thevalve.

1-. In valve mechanism for motors and the like, a valve, valve operatingmechanism which includes actuating means and a train of connections forcommunicating the valve opening motion of the said actuating means tothe valve, said train of connections including a shoe support and a shoesupported thereon through a resilient arm, said arm being so mountedupon said support as to normally maintain said arm in a condition offiexure adapted to cause the lower surface of said shoe to bear againstthe connection contiguous thereto with a pressure suflicient to take upthe lost motion in said train of connections, the adjacent surfaces ofsaid arm and said support being so formed that the 'further flexing ofsaid arm causes said adj acent surfaces to close together and togradually bring said shoe into rigid contact with said shoe support,'sothat thereafter said shoe serves to transmit the further valve openingmotion of the actuating means to to valve.

GEORGE A. SUFFA.

